The present invention relates to the diamond film deposition art. Specifically, a technique for producing diamond film deposition at low temperatures is described.
Manufacture of electronics components in many instances requires hard surface coatings to protect underlying materials. In the microelectronic art, a substrate including a microelectronic circuit is coated with a vinyl protective packaging layer which keeps the surface of the substrate bearing the electronics components free from contamination. Similarly, magnetic disk media used as a memory medium in computer disk drives also require on the surface thereof a protective film which is both hard and insulating and which does not interfere with the reading and writing of data to the disk. Additionally, future uses of diamond surfaces in the manufacture of computer chip substrates will offer a durability and heat transfer capability which exceeds current substrate design. These materials, because of their ability to shed heat, will permit higher density circuits to be fabricated.
The present techniques for forming diamond films often require the use of high temperatures and/or the presence of numerous contaminants. In order to produce a diamond film of sufficient purity, a tedious measurement and system monitoring are inefficient for high volume, low cost applications.
References in the prior art which describe these various techniques for growing synthetic diamond films include U.S. Pat. Nos. 4,191,735, 3,961,103 and 4,486,286. These techniques employ the use of a plasma for generating ion particles. In U.S. Pat. No. 3,961,103, the extracted ions are used to bombard a cathode to sputter or vaporize atoms of a desired material into a discharge space where they are ionized. The plasma therefore contains large concentrations of ions of a desired species, as well as a concentration of contaminants of an undesired species. The substrate upon which the diamond film is grown is directly exposed to excessive heat and contaminants.
The present invention provides a technique which will yield a relatively pure diamond film at moderate temperatures, which do not adversely effect typical electronic circuit substrates.